(a) Field of the Invention
This invention relates to 5-(aromatic-heteryl)-1,6-naphthyridin-2(1H)-ones, their cardiotonic use, their preparation and intermediates.
(b) Information Disclosure Statement
Hawes and Gorecki, J. Med. Chem. 16, 849-853 (1973), show, inter alia, the preparation of 2-hydroxy-3-(3-pyridinyl)-1,6-naphthyridine, tautomer of 3-(3-pyridinyl)-1,6-naphthyridin-2(1H)-one, by condensing 4-aminonicotinonitrile with ethyl 3-pyridinylacetate. Said 2-hydroxy-3-(3-pyridinyl-1,6-naphthyridine is an intermediate for preparing 2-amino-3-(3-pyridinyl)-1,6-naphthyridine, a potential diuretic agent. Also shown as potential diuretic agents are 2-amino-3-(2-furyl)-1,6-naphthyridine and 2-amino-3-(2-thienyl)-1,6-naphthyridine.
Lesher and Singh in U.S. Pat. No. 4,415,580, issued Nov. 15, 1983, show as cardiotonic agents 5-(lower-alkyl)-1,6-naphthyridin-2(1H)-ones (I) and their preparation by reacting a 5-(lower-alkanoyl)-6-methyl-2(1H)-pyridinone with di-(lower-alkyl)formamide di-(lower-alkyl) acetal to produce 5-(lower-alkanoyl)-6-[2-(di-lower-alkylamino)ethenyl]-2(1H)-pyridinone (II) and reacting II with formamidine or ammonia or salt thereof to produce I.
Lesher and Singh in U.S. Pat. No. 4,412,077, issued Oct. 25, 1983, show as cardiotonic agents 5-(lower-alkanoyl)-6-(lower-alkyl)-2(1H)-pyridinones (I) and their preparation by reacting 2-(lower-alkanoyl)-1-(lower-alkyl)-ethenamine (II) with a lower-alkyl 2-propynoate.
Copending U.S. patent application Ser. No. 630,810, filed July 13, 1984, discloses and claims 5-phenyl and selected 5-(substituted-phenyl)-1,6-naphthyridin-2(1H)-ones, their cardiotonic use, their preparation and intermediates.